The "raw" tape features previously unheard efforts from the band
His new covers LP is expected to arrive later this year
He said the way DOOM put words together was "often shocking in it’s genius"
"Well, the goats wanted me to play this. I don’t really think it’s appropriate"
"I hope that somehow we can be part of making music for you soon"
Fans can edit the card artwork and greeting message to send to their friends
The range is priced from £20 to £35
"If musicians can't afford to pay the rent...we haven't got tomorrow's music in place"
All proceeds will go to a testicular cancer charity
"I’m trying to make pictures that elicit some kind of happiness"